diff --git a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
index 195658fb77f..82b518edfa4 100644
--- a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp
@@ -267,49 +267,6 @@ void BlockFormattingContext::compute_width_for_block_level_replaced_element_in_n
     box.set_width(compute_width_for_replaced_element(box));
 }
 
-float BlockFormattingContext::compute_auto_height_for_block_level_element(const Box& box)
-{
-    Optional<float> top;
-    Optional<float> bottom;
-
-    if (box.children_are_inline()) {
-        // If it only has inline-level children, the height is the distance between
-        // the top of the topmost line box and the bottom of the bottommost line box.
-        if (!box.line_boxes().is_empty()) {
-            for (auto& fragment : box.line_boxes().first().fragments()) {
-                if (!top.has_value() || fragment.offset().y() < top.value())
-                    top = fragment.offset().y();
-            }
-            for (auto& fragment : box.line_boxes().last().fragments()) {
-                if (!bottom.has_value() || (fragment.offset().y() + fragment.height()) > bottom.value())
-                    bottom = fragment.offset().y() + fragment.height();
-            }
-        }
-    } else {
-        // If it has block-level children, the height is the distance between
-        // the top margin-edge of the topmost block-level child box
-        // and the bottom margin-edge of the bottommost block-level child box.
-        box.for_each_child_of_type<Box>([&](Layout::Box& child_box) {
-            if (child_box.is_absolutely_positioned())
-                return IterationDecision::Continue;
-            if ((box.computed_values().overflow_y() == CSS::Overflow::Visible) && child_box.is_floating())
-                return IterationDecision::Continue;
-
-            float child_box_top = child_box.effective_offset().y() - child_box.box_model().margin_box().top;
-            float child_box_bottom = child_box.effective_offset().y() + child_box.height() + child_box.box_model().margin_box().bottom;
-
-            if (!top.has_value() || child_box_top < top.value())
-                top = child_box_top;
-
-            if (!bottom.has_value() || child_box_bottom > bottom.value())
-                bottom = child_box_bottom;
-
-            return IterationDecision::Continue;
-        });
-    }
-    return bottom.value_or(0) - top.value_or(0);
-}
-
 void BlockFormattingContext::compute_height(Box& box)
 {
     auto& computed_values = box.computed_values();
diff --git a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.h b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.h
index 7cc5d6fac53..13852f74deb 100644
--- a/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.h
+++ b/Userland/Libraries/LibWeb/Layout/BlockFormattingContext.h
@@ -56,8 +56,6 @@ private:
 
     void compute_width_for_block_level_replaced_element_in_normal_flow(ReplacedBox&);
 
-    [[nodiscard]] static float compute_auto_height_for_block_level_element(const Box&);
-
     void layout_initial_containing_block(LayoutMode);
 
     void layout_block_level_children(Box&, LayoutMode);
diff --git a/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
index 5df5ba312f8..dfda823476c 100644
--- a/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
@@ -180,6 +180,63 @@ static Gfx::FloatSize solve_replaced_size_constraint(float w, float h, const Rep
     return { w, h };
 }
 
+float FormattingContext::compute_auto_height_for_block_level_element(const Box& box)
+{
+    Optional<float> top;
+    Optional<float> bottom;
+
+    if (box.children_are_inline()) {
+        // If it only has inline-level children, the height is the distance between
+        // the top of the topmost line box and the bottom of the bottommost line box.
+        if (!box.line_boxes().is_empty()) {
+            for (auto& fragment : box.line_boxes().first().fragments()) {
+                if (!top.has_value() || fragment.offset().y() < top.value())
+                    top = fragment.offset().y();
+            }
+            for (auto& fragment : box.line_boxes().last().fragments()) {
+                if (!bottom.has_value() || (fragment.offset().y() + fragment.height()) > bottom.value())
+                    bottom = fragment.offset().y() + fragment.height();
+            }
+        }
+    } else {
+        // If it has block-level children, the height is the distance between
+        // the top margin-edge of the topmost block-level child box
+        // and the bottom margin-edge of the bottommost block-level child box.
+        box.for_each_child_of_type<Box>([&](Layout::Box& child_box) {
+            if (child_box.is_absolutely_positioned())
+                return IterationDecision::Continue;
+            if ((box.computed_values().overflow_y() == CSS::Overflow::Visible) && child_box.is_floating())
+                return IterationDecision::Continue;
+
+            float child_box_top = child_box.effective_offset().y() - child_box.box_model().margin_box().top;
+            float child_box_bottom = child_box.effective_offset().y() + child_box.height() + child_box.box_model().margin_box().bottom;
+
+            if (!top.has_value() || child_box_top < top.value())
+                top = child_box_top;
+
+            if (!bottom.has_value() || child_box_bottom > bottom.value())
+                bottom = child_box_bottom;
+
+            return IterationDecision::Continue;
+        });
+        // In addition, if the element has any floating descendants
+        // whose bottom margin edge is below the element's bottom content edge,
+        // then the height is increased to include those edges.
+        box.for_each_child_of_type<Box>([&](Layout::Box& child_box) {
+            if (!child_box.is_floating())
+                return IterationDecision::Continue;
+
+            float child_box_bottom = child_box.effective_offset().y() + child_box.height();
+
+            if (!bottom.has_value() || child_box_bottom > bottom.value())
+                bottom = child_box_bottom;
+
+            return IterationDecision::Continue;
+        });
+    }
+    return bottom.value_or(0) - top.value_or(0);
+}
+
 float FormattingContext::tentative_width_for_replaced_element(const ReplacedBox& box, const CSS::Length& width)
 {
     auto& containing_block = *box.containing_block();
@@ -487,7 +544,16 @@ void FormattingContext::compute_height_for_absolutely_positioned_non_replaced_el
     box.box_model().padding.top = computed_values.padding().top.resolved_or_zero(box, containing_block.width()).to_px(box);
     box.box_model().padding.bottom = computed_values.padding().bottom.resolved_or_zero(box, containing_block.width()).to_px(box);
 
-    if (specified_height.is_auto() && !specified_top.is_auto() && !specified_bottom.is_auto()) {
+    if (specified_height.is_auto() && !specified_top.is_auto() && specified_bottom.is_auto()) {
+        const auto& margin = box.box_model().margin;
+        const auto& padding = box.box_model().padding;
+        const auto& border = box.box_model().border;
+
+        specified_height = CSS::Length(compute_auto_height_for_block_level_element(box), CSS::Length::Type::Px);
+        box.box_model().offset.bottom = containing_block.height() - specified_height.to_px(box) - specified_top.to_px(box) - margin.top - padding.top - border.top - margin.bottom - padding.bottom - border.bottom;
+    }
+
+    else if (specified_height.is_auto() && !specified_top.is_auto() && !specified_bottom.is_auto()) {
         const auto& margin = box.box_model().margin;
         const auto& padding = box.box_model().padding;
         const auto& border = box.box_model().border;
diff --git a/Userland/Libraries/LibWeb/Layout/FormattingContext.h b/Userland/Libraries/LibWeb/Layout/FormattingContext.h
index aad024a04e8..213be06a1b9 100644
--- a/Userland/Libraries/LibWeb/Layout/FormattingContext.h
+++ b/Userland/Libraries/LibWeb/Layout/FormattingContext.h
@@ -58,6 +58,7 @@ protected:
         float preferred_minimum_width { 0 };
     };
 
+    static float compute_auto_height_for_block_level_element(const Box& box);
     static float tentative_width_for_replaced_element(const ReplacedBox&, const CSS::Length& width);
     static float tentative_height_for_replaced_element(const ReplacedBox&, const CSS::Length& width);